Vehicles using ejector blades to remove material carried within the vehicle are well known, and the ejector blades of such vehicles are connected to a hydraulic cylinder or ram which is used to move the ejector blade from a load position to a discharge position for removing the material from the vehicle. When the ejector blade is in the load position, material may be freely loaded into the vehicle for transport to another location. When the ejector blade is moved from the load position towards the discharge position, materials loaded into the vehicle are discharged therefrom by the ejector blade pushing the materials from the body of the vehicle out through an unloading gate.
Because the ejector blade is secured to the hydraulic cylinder or ram for movement with the piston portion thereof, it has been experienced that when a vehicle such as an off-highway truck is traveling unloaded over rough and uneven terrain, the hydraulic cylinder will sometimes become partially extended. This unwanted extension of the hydraulic cylinder is referred to as cylinder "move out". Such cylinder "move out" can result in damage to the hydraulic cylinder during subsequent loading operation, and the resultant movement of the ejector blade out from the load position during loading of the vehicle can result in the ejector blade being twisted during loading operations damaging the ejector blade and/or the hydraulic cylinder to which it is attached.
In U.S. Pat. No. 5,456,521, there is disclosed one attempt to overcome the problem of the ejector blade not being held or locked in the load position for use with an off-highway dump truck body. To this end, a pair of U-shaped brackets are used to engage a pair of pins secured to the carriage of the ejector blade when the ejector blade is in the load position. The U-shaped brackets are rotated to disengage the pins by operation of the hydraulic cylinders which are actuated in conjunction with the tilting of the body for dumping and thereby release the ejector blade so that it scrapes and cleans the inside of the truck body as the ejector blade moves towards the unloading gate.
In U.S. Pat. No. 4,576,540, there is disclosed another system for retaining an ejecting mechanism in a load position which utilizes electrically controlled solenoids to actuate tipping or tripping locks which retain the ejector mechanisms in a load position until such time as they are used to discharge material from the vehicle.
This invention is directed to overcoming one or more of the problems or concerns set forth above.